Telephone sequential number dialer with number incrementing

ABSTRACT

A telephone sequential dialer features a shift register which has a number of bit positions which are one more than the maximum number of digits to be dialed. A plurality of consecutive ONES starting at the leading edge of the shift register are inserted into it, the number of ONES inserted being equal to the difference between the number of shift register bit positions and the number of digits of the telephone number to be called. The digits of the telephone number to be called are inserted into a counter whenever a ONE is detected in the shift register by a scanning means, and a dial pulse is generated whenever the counter is decremented. The dial pulses are no longer generated when the counter reaches zero.

This is a division of application Ser. No. 799,141, filed May 23, 1977.

BACKGROUND OF THE INVENTION

This invention relates to message announcement and response recordingsystems, and, more particularly, to telephone polling apparatus forsupplying a prerecorded message to a plurality of telephone subscriberstations in sequence and recording responses from the stations aftersupplying the message thereto.

Telephone polling has, in recent years, gained popularity as a means forreaching a large number of people on an individual, personalized basis,in order to deliver a message, such as a commercial advertisement or asales solicitation. Typically, in the past, such polling has beenachieved by utilizing manual dialing and message delivery, which isrelatively expensive. Additionally, this manual method of polling issusceptible to human dialing error, resulting in either wrong numbersbeing dialed or the same number being dialed more than once.

To overcome certain of the disadvantages of a manual pollingarrangement, different systems have been devised to effect the automaticsequential dialing and announcement function. For example, U.S. Pat. No.3,943,289 discloses apparatus wherein a prerecorded message is suppliedto a plurality of telephone subscriber numbers automatically called insequence from a local station. Upon placing the call to the firstnumber, another second number is established by changing the firstcalled number by a predetermined increment. In response to the firstcalled number being reached, the prerecorded message is coupled to atelephone line at the local station. In response to the call beingeither completed or the elapse of a predetermined time during which itis expected that the called subscriber should answer the telephone, atermination signal is derived to indicate that operations for the firstparty have been terminated. In response to the termination signal, thetelephone is repeatedly hung up and picked up automatically until theprerecorded message has been completed and a dial tone has beendetected, at which time the second number is called. The device isactivated repeatedly in this manner.

However, the apparatus disclosed in the aforementioned patent suffersfrom a number of disadvantages. For example, no response recordingcapability is disclosed, although it is mentioned that such can beprovided. Such response recording capability is advantageous when makinga sales solicitation because the called party can be requested to supplyhis name and telephone number, or address, for future follow-up by asales person. Additionally, it would be desirable to have responserecording capability wherein the response time is selectively adjustabledependent upon the type of information it is desired to record duringthe response. A further disadvantage of the apparatus disclosed in thepatent is that the disclosed apparatus will deliver a message even ifthe called number is answered by a telephone answering device whichdelivers a recorded message. This is an obvious undesirable attribute.

It is therefore an object of the present invention to provide apparatusfor supplying a prerecorded message to a plurality of telephonesubscriber stations in sequence and recording responses from thestations after supplying the message thereto.

It is another object of the present invention to provide such apparatuswherein the response recording time is selectively adjustable.

It is a further object of the present invention to provide suchapparatus which, after placing the call, can discriminate between a busycondition, an answer condition, a recorded announcement condition, and ano answer condition, on the telephone line, so that message delivery isonly effected upon discrimination of an answer condition.

It is still another object of the present invention to provide suchapparatus wherein the number of calls to be made and the initial phonenumber to be called may be readily programmed into the apparatus.

It is still a further object of the present invention to provide suchapparatus wherein the phone number being called and the number of callsstill to be made are displayed.

It is yet another object of the present invention to provide suchapparatus wherein message delivery and response recording may bemonitored by an operator.

It is yet a further object of the present invention to provide suchapparatus wherein the present activity of the apparatus, such asdialing, message delivery, etc., is displayed.

SUMMARY OF THE INVENTION

The foregoing and additional objects are attained in accordance with theprinciples of this invention by providing apparatus for supplying aprerecorded message to a telephone line. The apparatus comprises dialingmeans responsive to a start signal for providing dial signals indicativeof a telephone number to said telephone line and a number completesignal upon completion of said providing; means rendered effective bysaid number complete signal and responsive to energy on said telephoneline for providing a first signal in response to an energy condition onsaid telephone line indicative of an answer condition and providing asecond signal in response to an energy condition on said telephone lineindicative of a condition other than said answer condition; meansresponsive to said first signal for transmitting said prerecordedmessage over said telephone line; means responsive to the end of saidprerecorded message for generating said second signal; and meansresponsive to said second signal for providing said start signal.

In accordance with an aspect of this invention, the apparatus includesmeans for storing the telephone number to be called and means responsiveto the number complete signal for incrementing the stored telephonenumber by a predetermined number.

In accordance with another aspect of this invention, the apparatusincludes means responsive to the end of the message for coupling arecording medium to the telephone line and means responsive to the endof the message for timing a predetermined interval and generating saidsecond signal at the termination of the predetermined timed interval.

In accordance with yet another aspect of this invention, the apparatusincludes means for selectively adjusting the predetermined interval soas to provide response recording time adjustment.

In accordance with a further aspect of this invention, the apparatusincludes means whereby the message announcement and response recordingmay be monitored by an operator.

In accordance with still another aspect of this invention, the initialphone number to be called and the number of calls to be made are readilyprogrammed into the apparatus.

In accordance with yet a further aspect of this invention, there isprovided a visual display showing the phone number being called, thenumber of calls still to be made and the present activity of theapparatus.

DESCRIPTION OF THE DRAWING

The foregoing will be more readily apparent upon reading the followingdescription in conjunction with the drawing in which:

FIG. 1, which comprises FIGS. 1A and 1B with FIG. 1A placed to the leftof FIG. 1B, depicts a functional block schematic diagram of apparatusconstructed in accordance with the principles of this invention;

FIG. 2 depicts a schematic diagram of circuitry for detecting energy onthe telephone line and providing an output signal upon detection of suchenergy;

FIG. 3 depicts a functional block schematic diagram of discriminationcircuitry for timing the energy detection of the circuitry of FIG. 2 anddiscriminating between different conditions on the telephone line;

FIG. 4 depicts a functional block schematic diagram of circuitry forgenerating dial pulses to dial a telephone number;

FIG. 5 depicts a flow chart for the circuitry shown in FIG. 3 showingthe algorithm for discriminating between different conditions on thetelephone line;

FIG. 6 depicts a flow chart which will be helpful in understanding thefunctioning of the circuitry of FIG. 4 for dialing a telephone number;and

FIG. 7 depicts a flow chart for the apparatus of FIG. 1 depicting thesteps in recording a response.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, depicted therein is an overall block schematicdiagram of apparatus constructed in accordance with the principles ofthis invention which functions to supply a prerecorded message to aplurality of telephone subscriber stations in sequence and subsequentlyrecord responses from the stations after supplying the message thereto.The apparatus shown in FIG. 1 is coupled to a telephone line through atelephone operating company supplied coupler. The apparatus includes acontrol panel containing a keyboard and display. The keyboard isutilized to program the apparatus by keying in the initial phone numberto be called and the number of calls to be made. The display is fordisplaying the telephone number being called, the number of calls to bemade, and also includes indicators for displaying the system status,such as whether the apparatus is in the dial mode, the message deliverymode, the response recording mode, plus indicators as to the conditionof the power supply. The control panel also includes control switcheswhich will be described in more detail hereinafter.

The apparatus shown in FIG. 1 also includes an announcement recorderwhich contains the prerecorded message on an endless loop tape and aresponse recorder which is illustratively a tape cassette recorder intowhich blank recording tape cassettes are inserted.

The initial phone number to be called is entered by an operator via the12-station keyboard 10. The keyboard data is encoded into a BCD formatby encoder 12 and stored in 11-digit memory/counter 14. The number ofdigits required is dependent on the type of call: i.e., local, locallong distance, and long distance. A 3-digit memory/counter register 16is provided to store the number of calls to be made. Phone numbers, orthe number of calls, are programmed by first depressing the * button or# button on the keyboard respectively, with Program/Run switch 18 in theProgram position.

Programmed information is shown by a 14-digit display 20. Displayed datais controlled by a BCD to 7 segment decoder driver 22 and digit scanner24. Once the initial data is entered and visually checked, theProgram/Run switch 18 is set to Run.

The telephone is electronically taken off hook by operating dial relay26 to close the OH1 and OH2 contacts connected to the coupler. The dialtone appearing across the tip and ring connection of the audiotransformer 28 is coupled to filter 30 and analog gate 32. Dial tonesare passed by gate 32, amplified by amplifier 34, and presented to tonedecoder 36 via a summing network 38. In response to the 440 Hz dial tonesignal, tone decoder 36 provides a signal to set dial enable flipflop40. If no tone appeared within 40 seconds, the phone is placed back onhook for a period of eight seconds before a new attempt is made.

All signals appearing on the telephone line are also presented to poweramplifier 42 which drives speaker 44. This allows an operator to monitorevents as desired. Once set, enable dial flipflop 40 turns on dial light46 and enables encoded dial data to be presented to dial relay 26.Numbers are dialed by opening and closing the OH1 and OH2 contacts. Whenthe dialed number is completed, enable dial flipflop 40 is reset andenable ring/busy/answer flipflop 48 is set, and dial light 46 isextinguished.

Detection of rings, busy signals or answers is accomplished by timing avoice activated device (VOX) 50. Conventional methods of ring and busydetection through use of tone decoders presents problems due toinconsistencies between local telephone companies with respect tosignalling frequencies. Ring and busy frequencies vary from exchange toexchange with no nationwide standard expected until the year 2000.

VOX 50 and associated timer 52 together form a timed energy detector.Logic is provided to discriminate between ring and busy signals. Oncethe phone is answered, additional discrimination is provided todetermine if the answering party is a legitimate subscriber or recordedannouncement.

In the event that the call is not answered, the line is busy, or arecorded announcement is on the line, the phone is hung up, phone numbercounter 14 is incremented by a fixed number, illustratively 10, andnumber of calls counter 16 decremented by one.

Detection of a valid answer sets enable announce flipflop 54 and clearsenable ring/busy/answer flipflop 48. Announce light 56 is illuminated.Concurrently, announcement recorder 58 is turned on by remote announcerelay 60.

The recorded announcement is passed by analog gate 62, amplified byamplifier 64, and presented to the phone line. A tone at the samefrequency as the dial tone signals the called party that theannouncement is completed. This same tone is presented to tone decoder36 via summing network 38. Detection of the tone resets enable announceflipflop 54 and conditionally sets enable response flipflop 66. Useageof a tone permits variable length announcements within the time limitsof endless loop tapes.

Enable response flipflop 66 will be set by response recorder control 67provided that response time switch 68 is not set to zero. In this event,the logic is cleared to its starting condition and the next number isprocessed. Once enable response flipflop 66 is set, record light 70 isilluminated and response recorder 72 turned on through relay 73. Signalsfrom the phone line are amplified by amplifier 74 and presented torecorder 72 via summing network 76. If no signals are detected, or if adial tone is detected within a 4-second interval, enable responseflipflop 66 is reset, signalling the start of a new cycle.

If the called party continues to respond, the recorder 72 will remain onfor the duration of the response time setting. A new cycle is theninitiated.

The announcement tape is programmed by inserting the endless loop tapeinto response recorder 72, and placing the unit in the program mode ofoperation. Signals from microphone 78 are presented to recorder 72 viasumming network 76. Depressing record tone switch 80 gates a 440 Hzsignal to the recorder from tone decoder 36 through gate 81 for aduration of 800 milliseconds, as determined by timer 82.

The overall system is under the control of timing and control circuit84, which provides control signals at the proper times and in thecorrect sequence to the various circuits in the apparatus. Basic timingis provided by oscillator 86.

The apparatus is designed to be powered by standard utility supplied 60Hz 117 volt AC power. This is converted to 9 volt DC power by supply 88to power all the logic circuitry. In the event of a power failure, thereis also provided 9 volt battery 90 to insure integrity of memories 14and 16. Comparator 92 provides a signal to disable the apparatus ifbattery 90 is not at full potential.

Referring now to FIG. 2, VOX 50 is coupled to receive the output ofamplifier 34, whose input is derived from signals on the telephone line.VOX 50 consists of a halfwave rectifier with preset squelch and twointegrating circuits. The first integrating circuit is a fast attack,slow decay integrator to smooth the rectifier output so as to provide avoltage corresponding to the average energy level of the audio input.The output of this integrating circuit is fed to a comparator. If theaverage energy level is above a preset bias the comparator is turned on.The output of this comparator is integrated by a slow attack, fast decaycircuit to eliminate high energy, short duration, switching noises onthe telephone line. The resulting signal is the input to anothercomparator. When this signal is above a preset bias, the output of theVOX is a logic ONE.

The aforementioned halfwave rectifier with preset squelch is comparator102, which is a rectifier with a bias. When the output of amplifier 34on the non-inverting input of comparator 102 is higher than the biasapplied to the inverting input of comparator 102, the output ofcomparator 102 on line 104 is high. Inverter 106 inverts the signal onlead 104 to provide a low signal at its output on lead 108, dischargingcapacitor 110. When the voltage across capacitor 110 gets below the biasinput to comparator 112, the output of comparator 112 on lead 114 goeshigh. Capacitor 116 then charges. When the voltage across capacitor 116gets above the bias voltage applied to the inverting input of comparator118, comparator 118 provides a high signal (a logic ONE) at VOX output120. When there is no energy on the telephone line, the output ofcomparator 102 is low, causing the output of inverter 106 to be high,charging capacitor 110, placing a low signal on the output of comparator112, discharging 116, and providing a low signal (a logic ZERO) at VOXoutput 120.

Illustratively, resistor 122 has a value of 100K ohms, resistor 124 hasa vlaue of 4K ohms, resistor 126 has a value of 22K ohms, and resistor128 has a value of 4K ohms. Because of these relative resistance value,the integrating circuit of which capacitor 110 is a part, is a fastattack, slow decay integrator because capacitor 110 discharges veryquickly through the 4K ohm resistor 124 and charges much slower throughthe 104K ohm resistance combination of resistors 122 and 124. Thisintegrating circuit smooths the rectifier output to provide a voltagecorresponding to the average energy level of the audio input. The otherintegrating network, comprising resistors 126 and 128 and capacitor 116is a slow attack, fast decay circuit wherein when there is energy on thetelephone line, capacitor 116 charges through a 26K ohm path and whenthere is no energy detected on the telephone line, capacitor 116discharges quickly through a 4K ohm path. The purpose of thisarrangement is to kill short duration pulses which get through the firstintegrating network because of its fast attack characteristic.

VOX enable terminal 130 is utilized to selectively enable and disableVOX 50. When a low level is applied to terminal 130, the output ofcomparator 102 is clamped low, keeping the output of inverter 106 highshich allows capacitor 110 to charge, thereby keeping the output ofcomparator 112 low, which keeps capacitor 116 discharged and VOX outputterminal 120 is maintained low. To enable VOX 50, VOX enable terminal130 is allowed to float, with no voltage being applied thereto. Toaccomplish the aforedescribed function, VOX enable terminal 130 isconnected to an open collector gate 132 (FIG. 1).

Referring now to FIG. 3, functionally depicted therein is circuitryresponsive to the output of VOX 50 for discriminating between differentconditions on the telephone line. To determine that a call has beenanswered, it is first necessary to determine that at least one ring hasappeared on the telephone line. A discrimination that this first ringhas appeared on the telephone line is determined by a continuous VOXoutput of at least 900 milliseconds. After the first ring signal, if 40seconds elapse before an answer is detected, the apparatus automaticallyterminates the telephone connection. If, after one or more rings, thecalled party answers the phone by lifting the receiver and saying"Hello", a normal response, the VOX will be activated by the "Hello" onthe line. This word is normally more than 200 milliseconds but less than1.2 seconds in duration. Thus, a VOX output for more than 200milliseconds but for less than 1.2 seconds is considered to be ananswer. If the called party merely lifts the receiver without sayinganything, silence on the line for 8 seconds is also considered to be ananswer. The call may also be answered by a recorded message which willappear on the line either because the number called is intercepted bythe telephone company or an automatic telephone answering device is inuse at the called number. In either case, a message of 10 seconds ormore duration will appear on the telephone line. Because of naturalpauses between words, the VOX output will not remain high during theentire message. However, it has been found that under suchcircumstances, the VOX output will remain high more than 80 percent ofthe time. If the VOX output is high more than 80 percent of the time forapproximately five seconds, the apparatus is caused to automaticallyhand up. The final telephone line condition which is discriminated isthe presence of a busy signal on the telephone line. These signals arenominally 500 milliseconds in duration alternating with 500 millisecondsof silence. Since the busy signals are less than 900 milliseconds induration, a ringing condition in not detected. Since each is greaterthan 400 milliseconds in duration, a busy counter is incremented. Whenthe busy counter reaches a count of eight, the apparatus is caused toautomatically hang up.

In summary, then, the discrimination of telephone line conditions is asfollows:

BUSY: 8 VOX activations of more than 400 milliseconds but less than 900milliseconds;

FIRST RING: VOX activation of more than 900 milliseconds;

SUBSEQUENT RING: VOX activation of more than 1.2 seconds but less than50 percent VOX activity for any five second period;

ANSWER: VOX activation of more than 200 milliseconds but less than 1.2seconds or eight seconds of inactivity of the VOX after the first ring;

RECORDED MESSAGE: VOX activation during 80 percent of any five secondinterval; and

NO ANSWER: Expiration of 40 second timer.

To understand how the foregoing is accomplished, the reader is referredto FIG. 3 which depicts, in functional form, circuitry for accomplishingthe discrimination discussed above. The design of particular circuitryfor implementing the functional blocks shown in FIG. 3 will be apparentto one of ordinary skill in the art, standard integrated circuitbuilding blocks being commercially available to implement the differentfunctions. FIG. 3 is a functional simplification of circuitry within VOXtimer and announce recorder control circuit 52 (FIG. 1), certainparticular details of the circuitry not being shown, such as, forexample, all the timing leads from timing and control circuit 84 (FIG.1). The following description of FIG. 3 follows the flow chart shown inFIG. 5. The circuitry of FIG. 3 and the flow chart of FIG. 5 functionafter a number is dialed. The dialing will be described in more detailhereinafter with reference to FIGS. 4 and 6.

After a number is dialed, VOX 50 is enabled, busy counter 150 is enabled(by means not shown) and 40 second timer 152 is enabled (also by meansnot shown). The circuitry shown in FIG. 3 causes either answer flipflop154 or repeat flipflop 156 to be set as a consequence of the particularcondition discriminated. Answer flipflop 154 is set only when a validanswer is detected. Repeat flipflop 156 is set either when the 40 secondtimer 152 times out due to continued ringing, or a busy condition isdetected, or a recorded message is sensed on the telephone line. Whenanswer flipflop 154 is set, the recorded announcement is transmittedover the telephone line. When repeat flipflop 156 is set, the connectionto the telephone line is terminated by the apparatus hanging up and thestart of a new call is initiated, in a manner to be describedsubsequently. Timer 152 is reset after detection of a line condition (bymeans not shown).

With VOX 50 enables, when the first ring appears on the telephone line,terminal 120 is high. This high signal is inverted by inverter 158 toprovide a low signal to the enable input of counter 160, enablingcounter 160 to begin counting the 10 hertz pulses on its input lead 162.These 10 hertz pulses are supplied by timing and control circuit 84(FIG. 1). When counter 160 reaches a count of 8, this indicates that 800milliseconds of VOX detected energy on the telephone line has occurred.This provides a high signal on lead 164 to the D input of flipflop 166.When counter 160 reaches a count of 9, lead 168 also goes high, clockingand setting flipflop 166 so that its Q output on lead 170 goes high,flipflop 166 having previously been cleared by the VOX input on terminal120 being low. With a high signal on lead 170, counter 160 is set to aninternal count of 9 and is held at that count as long as the high signalpersists on lead 170. When the Q output of flipflop 166 went high at thecount of 9 from counter 160, the Q output of flipflop 166 on lead 172went low, setting ringing flipflop 174. This setting of ringing flipflop174 indicates that 900 milliseconds of VOX activity has been detected.Before this setting of ringing flipflop occurred, when counter 160reached a count of 4, indicating 400 milliseconds of VOX activity, asignal on lead 176 caused busy counter 150 to be incremented. When busycounter 150 reaches a count of 8, it causes repeat flipflop 156 to beset through OR gate 178. However, as this is the start of a ringingcycle, busy counter is only at a count of 1. It will also be recalledthat 40 second timer 152 has been started. If 40 second timer 152 timesout, it will set repeat flipflop 156 through OR gate 178.

With ringing flipflop 174 set, a high signal appears at its Q output onlead 180. A high signal on lead 180 removes the clear input from onesecond one-shot 182. The high signal on lead 180 also partially enablesNAND gate 184. The other input to NAND gate 184 is the output ofinverter 186 whose input is the VOX output on terminal 120. With no VOXactivity, the output of inverter 186 on lead 188 will be high. With theconcurrence of no VOX activity and ringing flipflop 174 being set, theoutput of NAND gate 184 will enable counter 190 to count the one hertzpulses applied to its input on lead 192 from timing and control circuit84 (FIG. 1). When counter 190 reaches a count of 8, this indicates that8 seconds of silence on the telephone line have occurred at some pointafter a first ring has been detected. As discussed above, this isinterpreted as an answer. Therefore, with an output signal being appliedto lead 194 from counter 190, indicating that counter 190 has timed 8seconds of VOX inactivity after the ringing flipflop 174 has been set,ringing flipflop 174 is reset. The Q output of ringing flipflop 174 onlead 196 going high causes answer flipflop 154 to be set through OR gate198.

Assuming that subsequent ringing signals are detected, busy counter 150will be incremented after 400 milliseconds of each ringing signal. Sinceringing signals are spaced nominally six or seven seconds apart, 40second timer 152 will time out before busy counter 150 reaches a countof 8. However, if busy signals are detected on the line, these signalsonly last 500 milliseconds and busy counter 150 will be incremented onceeach second, therefore reaching a count of 8 in approximately 8 seconds,causing repeat flipflop 156 to be set.

Returning now to the condition of continued ringing, with ringingflipflop 174 set, the clear input is removed from one second one-shot182. After 200 milliseconds of VOX activity, one second one-shot 182 isfired by the signal on lead 183 from counter 160. At the end of its onesecond time period, 10 microsecond one-shot 202 is fired. 10 microsecondone-shot 202 is utilized to provide a strobe pulse on lead 204 whichchecks to see whether VOX activity still persists, as determined by thestate of flipflop 166. If VOX activity still persists, lead 172 will below. However, if there is no longer any VOX activity 1.2 seconds afterVOX activity has started, flipflop 166 will have been cleared and lead172 will be high, enabling AND gate 206 and causing answer flipflop 154to be set through OR gate 198. This condition is, as described above, avalid answer condition in that there has been VOX activity for at least200 milliseconds but for less than 1.2 seconds.

The last condition to be discriminated is the condition of a recordedannouncement, which is detected as 80 percent VOX activity for 5seconds. To detect such condition, there is provided resistor 208,capacitor 210, and comparator 212. Resistor 208 and capacitor 210 forman integrating network. Their values are illustratively chosen to be 1.2megohm for resistor 208 and 3.3 microfarads for capacitor 210. Thisprovides an approximately five second time constant and the referencevoltage applied to the inverting input of comparator 212 in combinationwith the resistance capacitance network causes a low signal to appear atthe output of comparator 212 on lead 214 after approximately fiveseconds of 80 percent VOX activity. This low signal on lead 214 causesbusy counter 150 to be set to 9. With busy counter 150 set to 9, its 8count output on lead 216 is high, causing repeat flipflop 156 to be setthrough OR gate 178. In other words, a recorded announcement on the lineis detected and the circuitry is logically set as if a busy conditionwere sensed.

Referring now to FIG. 4, functionally shown therein is a block schematicdiagram of circuitry for implementing the dialing function after dialtone is detected by tone decoder 36 (FIG. 1) and enable dial flipflop 40is set thereby. The following description of the circuitry shown in FIG.4 describes how the circuitry functions to follow the flow chart of FIG.6, and the reader is referred thereto during the following description.

Dialing is accomplished by alternately energizing and de-energizing dialrelay 26 (FIG. 1). Off-hook terminal 250 is connected to dial relay 26and a low signal at terminal 250 energizes relay 26. A high signal onterminal 250 de-energizes relay 26. When relay 26 is energized, itcloses the connection in the telephone coupler between OH 1 and OH 2,thereby providing an off-hook to the telephone line. During a telephoneconnection, the condition of the telephone line is normally off-hook.During dialing, a sequence of on-hooks alternating with off-hooks causesthe telephone switching equipment at the local telephone company centraloffice to count the number of on-hooks to determine the particular digitthat was dialed. During the telephone connection, phone digit flipflop252 is normally in a reset state so its Q output on lead 254 is high,causing NOR gate 256 to provide a low output on terminal 250. During thedialing, in a manner to be described hereinafter, phone digit flipflop252 is set so its Q output is low, causing the 10 hertz clock pulses onlead 258, supplied by timing and control circuit 84 (FIG. 1), togenerate alternate on-hook and off-hook signals at terminal 250. Thelength of time that phone digit flipflop 252 is set is determined by theparticular digit being dialed so that the proper number of 10 hertzclock pulses pass through NOR gate 256.

When it is desired to dial a phone number, a 40 second timer (not shown)is started and dial tone decoder 36 is monitored to determine whetherdial tone is detected within that 40 second period. If the 40 secondtimer completes timing the 40 second interval without dial tone beingdetected, repeat flipflop 156 is set (FIG. 3, by means not shown) torestart the cycle. When dial tone is detected, enable dial flipflop 40is set. This removes the clear from the phone digit flipflop 252,leaving a high signal on its Q output on line 254. At this time, pointershift register 260 is loaded, its contents indicating how many digitsare to be dialed, in a manner to be described by the following.

The number to be dialed is stored in 11 stage memory/counter 14. Thisnumber is stored in binary coded decimal (BCD) form. At this time, thenumber is to be displayed on display 20. An 11 phase clock over leads262 from timing and control circuit 84 (FIG. 1) sequentially causes theeleven possible phone digits to be outputed to BCD to 7 segmentdecoder/driver 22 which controls display 20. A telephone number beingdialed has at a maximum 11 digits: an initial ONE, three digits for thearea code, and seven digits for the local telephone number. Some ofthese digits may not be utilized, but in all cases, the first digit tobe dialed is not zero. Therefore, leading zeros are logically ignoredand displayed as blanks, not zeros. Decoder/driver 22 has an output lead264 that is high (a logical ONE) when a digit is blank. These are all inthe leading positions of the possible 11 digit phone number. It is thesesignals on lead 264 that are gated into pointer shift register 260 bythe 11 phase clock on leads 262. Pointer shift register 260 is a 12 bitshift register, its first bit position always being a ONE, the next fourbit positions indicating if there are blank digits not to be dialed, andthe last seven bit positions being ZERO. Therefore, the number oftrailing ZEROS in pointer shift register 260 corresponds to the numberof phone digits to be dialed for a particular phone number. The numberof leading ONES equals twelve minus the number of phone digits to bedialed.

After pointer 260 is loaded, and between successively dialed digits,there is a one second pause which is determined by examining the borrowoutput of digit counter 266 on lead 268. Digit counter 266 isdecremented by the 10 hertz clock pulses on lead 258. When enableflipflop 40 was set, digit counter 266 has been cleared to ZERO by thesignal on its clear input 270. When digit counter 266 is decremented, ittakes 10 pulses of the 10 hertz clock on lead 258 to bring digit counter266 back to ZERO again, at which time there is a low signal at itsborrow output on lead 268. At this time, phone digit flipflop 252 andread flipflop 270 are clocked. This does not change the state of phonedigit flipflop 252, because its Q output was already high. However, readflipflop 270 is clocked to provide a high signal on its Q output on lead272. This partially enables NAND gate 274. The other input to NAND gate274, called DATA READY, on lead 276 is the output of scanner 278.Scanner 278 utilizes the 11 phase clock on leads 262 to look at thefirst 11 bit positions of pointer 260. Whenever there is a ONE in one ofthe bit positions of pointer shift register 260, a DATA READY pulse onlead 276 is generated. This causes a pulse to be generated on lead 280which is the load input of digit counter 266. This causes thecorresponding digit of 11 stage memory/counter 14 to be loaded intodigit counter 266. As long as there is ONE in pointer shift register260, a digit is read into digit counter 266, but only the last digitread in will remain in digit counter 266; each time a digit is read init erases the previous digit read in. The load pulse on lead 280 alsopreset phone digit flipflop 252 to cause its Q output on lead 254 to golow. This allows the output of NOR gate 256 to be controlled by the 10hertz clock pulses on lead 258. It should be noted at this point thatthe ll phase clock on leads 262 are at a much faster rate than the 10hertz pulses on lead 258 so that during the time that theabove-mentioned loading of digit counter 266 has occurred, there havebeen no 10 hertz clock pulses on lead 258.

Now that a digit is stored in digit counter 266, the 10 hertz clockpulses on lead 258 decrement digit counter 266. Each time that a 10hertz clock pulse on lead 258 decrements digit counter 266 it alsogenerates an on-hook signal at lead 250. This continues until digitcounter 266 reaches zero, so that a number of on-hook pulses have beengenerated corresponding to the digit to be dialed. When digit counter266 reaches zero, its borrow output on lead 268 clocks phone digitflipflop 252 and read flipflop 270. (At this point it should be notedthat the decrementing occurs prior to checking the borrow output so thatif a phone digit were zero, ten dial pulses would have been generated).Since phone digit flipflop 252 had been in the set state with its Qoutput low, read flipflop 270 is clocked so that its Q output on lead282 is now high. Phone digit flipflop 252 is clocked so its Q output onlead 254 now goes high. The high output on lead 282 combines with theborrow output on lead 268 to generate a shift pointer signal on lead 284through NAND gate 286 and inverter 288. This shift pointer signal onlead 284 shifts the array of leading ONES in pointer 260 one positiontoward the trailing end.

At this time, digit counter 266 is decremented by the 10 hertz pulses onlead 258 to provide the one second interdigit pause. When digit counter266 again reaches ZERO, phone digit flipflop 252 and read flipflop 270are clocked. This causes the next digit in 11 stage memory/counter 14 tobe read into digit counter 266 because the last ONE bit in pointer shiftregister 260 has been moved one position toward the trailing end. Theaforedescribed cycle is repeated until the last phone digit of thenumber has been dialed. After the last phone digit has been dialed, whenpointer shift register 260 has its contents shifted, a ONE will appearin its twelfth bit position. This causes a number complete signal toappear on lead 290, which resets enable dial flipflop 40, terminatingthe dialing sequence.

After the number is dialed, the circuitry shown in FIG. 3 and discussedabove is utilized to discriminate between possible conditions on thetelephone line. In the event that the repeat flipflop 156 has been setdue to there being no answer, a busy condition, or a recordedannouncement detected on the telephone line, a clear pulse is caused tobe generated (by circuitry not shown), the apparatus terminates thetelephone connection, increments 11 stage memory/counter 14 by apredetermined number to generate a new number, decrements number ofcalls memory/counter 16, and if it is determined by the contents ofnumbers of calls memory/counter 16 that calls are still to be made, anillustratively 8 second interval is timed after which the telephoneconnection is placed in an off-hook condition and the apparatus againwaits to detect dial tone. In the event answer flipflop 154 had beenset, this causes enable announce flipflop 54 (FIG. 1) to be set totransmit a message over the telephone line. After transmission of themessage, enable response flipflop 66 will be set. If response timeswitch 68 is set to an ANNOUNCE ONLY position, enable response flipflop66 will be immediately reset which will set repeat flipflop 156 to startthe cycle over again.

Assuming that response time switch 68 is set to one of the selectedpositions (illustratively 4, 12 or 20 seconds of response recordingtime), a response timer within response recorder control 67 will bestarted. The reader is referred now to FIG. 7 which depicts a flow chartshowing how the apparatus functions to record a response. Assuming thereis a valid response on the telephone line, in a manner to be describedhereinafter, the setting of response time switch 68 causes the output ofthe response timer to be checked at corresponding time intervals and ifthe response timer reaches the set time, repeat flipflop 156 is set toinitiate a new cycle. To check that a valid response is on the line,after two seconds, VOX 50 is enabled. This is to give the called partyon the telephone line two seconds in order to think of something to say.If there is no output from VOX 50 at the end of four seconds, repeatflipflop 156 is set. If there is a VOX output detected, a responseflipflop within response recorder control 67 is set to indicated that avalid response has been detected. At this time, the outputs of VOX 50and tone decoder 36 are monitored. The concurrence of an output from VOX50 and tone decoder 36 indicates that dial tone is on the line becausethe called party has hung up after giving some response. This causesrepeat flipflop 156 to be set so that the apparatus terminates theconnection and calls the next telephone number in sequence.

Accordingly, there has been described apparatus according to theprinciples of this invention for supplying a prerecorded message to aplurality of telephone subscriber stations in sequence and recordingresponses from the stations after supplying the message thereto.Advantageously, the apparatus detects the presence of energy on thetelephone line and times such detection in order to discriminate betweendifferent conditions on the telephone line after the number is dialed.It is understood that the above-described arrangement is merelyillustrative of the application of the principles of this invention.Numerous other arrangements may be devised by those skilled in the artwithout departing from the spirit and scope of this invention as definedby the appended claims.

What is claimed is:
 1. Automatic telephone dialing apparatuscomprising:means for storing a telephone number to be called; a counter;a shift register having a leading end and a trailing end, the number ofbit positions in said shift register being one more than the maximumnumber of digits to be dialed; means for inserting in said shiftregister a plurality of consecutive ONES starting at said leading end,the number of ONES equaling the difference between the number of shiftregister bit positions and the number of digits of the telephone numberto be called; means for scanning said shift register bit positionsstarting at the leading end; means for inserting into said counter fromsaid storing means the digits of the stored telephone number in sequencein synchronism with the scanning of said shift register whenever a ONEis detected in a bit position of said shift register; means fordecrementing said counter; means responsive to said counter beingdecremented for generating a dial pulse; and means responsive to saidcounter reaching a count of zero for terminating said dial pulsegeneration.
 2. Automatic telephone dialing apparatus according to claim1 further including means responsive to said counter reaching zero forshifting the contents of said shift register one position toward itstrailing end.
 3. Automatic telephone dialing apparatus according toclaim 2 further including means responsive to the presence of a ONE inthe shift register bit position closest to the trailing end forterminating dialing of the telephone number to be called.
 4. Automatictelephone dialing apparatus according to claim 1 further including meansfor pausing a predetermined time between dialing of successive digits.5. Automatic telephone dialing apparatus according to claim 4 whereinsaid pausing means include means responsive to said counter being zerofor decrementing said counter to zero again.